Nuclear materials, materials made to last: materials put to the test in nuclear environments, ageing under close watch, a steel core for tomorrow's nuclear power plants

High temperatures, irradiation, mechanical stresses, corrosive environments, etc. The materials used in nuclear power plants are subjected to extreme conditions. Guaranteeing the safety, lifespan and performance levels of current reactors, while designing and qualifying new materials capable of resisting the specific constraints of future nuclear systems, are the main issues investigated at the CEA/DEN in the field of nuclear materials. To meet these requirements, researchers at the CEA have access to a wealth of feedback, skills and unparalleled experimental facilities. How can we describe materials? They play a vital role in civil nuclear engineering. The safety of nuclear power plants, not to mention their lifespan and their performance depend on materials. Researchers at the Nuclear Energy Division (DEN) in Saclay are able to study, develop and qualify a broad range of materials (metal alloys, composite materials, oxides, etc.) intended for both current and future reactors, thanks to the CEA's unique set of equipment. Ensuring that the materials used to make the non-moving parts of reactors age correctly and improving the safety and performance of other materials, such as fuel cladding: this is the aim of research conducted by the CEA/DEN on second-generation power plants which make up EDF's current nuclear fleet. Developing materials for future fast reactors is the other challenge facing the researchers at the CEA/DEN, who already have the benefit of feedback. It is a question of designing high-performance materials which are totally reliable and safe, especially those containing fuel or in contact with the sodium coolant. ODS steels appear to be excellent candidates. (authors)